Use size_t instead of int to support a cache larger than 2G

[TerryE]

Note that this isn't quit complete in that zend_shared_alloc.c:102 should be

static void no_memory_bailout(size_t allocate_size, char *error)
{
    zend_accel_error(ACCEL_LOG_FATAL, "Unable to allocate shared memory segment of %ld bytes: %s: %s (%d)", allocate_size, error?error:"unknown", strerror(errno), errno );
}

[dstogov]

Committed. Thanks.